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24 votes

Why are rings not a favorite option in IT networks?

Historically, there were several competing technologies using ring structures like Token Ring or FDDI, but due to higher cost, lower performance, or simply slower development they've all vanished. ...
Zac67's user avatar
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21 votes

Why are rings not a favorite option in IT networks?

The downside with ring networks as opposed to for example star networks, is that in a ring topology, any link in the ring needs to have enough capacity for all nodes on that ring, in order to be able ...
Teun Vink's user avatar
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14 votes

Cascading Switches. Will it affect performance?

Is this okay? Hardly ideal. I assume since you are using cheap, obsolete switches, that you're on a very limited budget. You'll have to weigh the factors below. Does a cascade of switches affect ...
Ron Trunk's user avatar
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10 votes

Why are rings not a favorite option in IT networks?

Historically, we did use ring topologies - e.g. token ring. It didn't have redundancy. Whenever the ring broke, the whole network went down. Bus topologies (Ethernet over coaxial) were a bit better in ...
fraxinus's user avatar
  • 269
8 votes

Cascading Switches. Will it affect performance?

There are several reasons for not chaining switches, all of which relate to performance with the parameters effective throughput, resilience, latency. As Ron has aptly pointed out, more aggregation ...
Zac67's user avatar
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7 votes
Accepted

F5 as a backbone router

Pushing full routes into a load balancer is about as far from best practice as you can get. Give it a default route to an actual router and a static route back to your subnets and it should be able ...
rnxrx's user avatar
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7 votes

Why are rings not a favorite option in IT networks?

I mean it's a great way of providing redundancy with low cost. That is true if and only if multiple faults don't happen at the same time and one fault is fixed before the next fault happens. ...
Peter Green's user avatar
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6 votes
Accepted

Valid use cases for packet deduplication?

Usually this is discussed in the context of network capture appliances. So - for example - if you have taps on four links and a given packet happens to traverse all four then you'll naturally see ...
rnxrx's user avatar
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6 votes
Accepted

Should a Metropolitan Area Network (MAN) be setup with a router at each site?

Yes. You do not want to extend Layer 2 MAN links beyond the border of each location - this is bad design for a number of reasons: You will extend the broadcast domain of all 5 sites up to the main ...
Benjamin Dale's user avatar
6 votes

Cascading Switches. Will it affect performance?

Additional comments: Remember to allow for growth too - no new switch should be installed fully populated. There should always be some spare ports. I've seen recommendations from 50% full to at ...
Criggie's user avatar
  • 717
6 votes

Cascading Switches. Will it affect performance?

This design is ok only if you are willing to accept a single point of failure for all office switches, web farm, sql, file-server and internet. This design is ok only if you are willing to accept ...
Mike Pennington's user avatar
5 votes
Accepted

What certifications are there for Fiber Optic termination and splicing?

It's not terribly difficult to train yourself, if you care about the doing. If you care about selling yourself more, BICSI will happily take your money as a certifier. Probably better if you can get ...
Ecnerwal's user avatar
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5 votes
Accepted

Internet structure and ISP networks in detail

You're mixing up a couple of things. Also be aware that Internet structures are very different in different countries. A DSLAM is part of the Digital Subscriber Line technology, delivering Internet ...
jonathanjo's user avatar
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5 votes
Accepted

why do we use a layer 2 switch in a DMZ rather than a layer 3?

A layer-3 switch is primarily a layer-2 switch, but with a routing module in it. A layer-3 switch that is not configured with multiple networks is simply a layer-2 switch. Routers, including the ...
Ron Maupin's user avatar
  • 99.4k
5 votes

why do we use a layer 2 switch in a DMZ rather than a layer 3?

A DMZ is a security construct. That's where one places machines that are inherently untrustworthy -- eg. an internet accessible web site that someone, at some point, is going to break into. As such, ...
Ricky's user avatar
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5 votes
Accepted

SFP to SFP going through multiple environments – segmented or via single cable?

should I use a single fiber between two server rooms or split it into segments for easier maintenance/replacement? Fiber doesn't require any maintenance. If you provide decent protection (duct, tube) ...
Zac67's user avatar
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5 votes

SFP to SFP going through multiple environments – segmented or via single cable?

Every connection introduces signal loss, albeit small. (at the distance you're talking, you could string together patch cables and still maintain enough signal for SR signaling.) It's common practice ...
Ricky's user avatar
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4 votes

Fiber Trenching Design (L1)

This is a budget question. The cheapest option is to daisy-chain each building. The "cost conscious" option is to link each building back to a central location. And finally, the most future-proof (and ...
Ricky's user avatar
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4 votes
Accepted

Need some advice with network topology

Your stack switches should be connected to both routers. That way, you will have redundancy if a router fails. If possible, your servers should also be dual-homed to both routers. VRRP will do you ...
Ron Trunk's user avatar
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4 votes
Accepted

Defining hierarchical BGP route-maps

In larger carriers it's actually a lot more common to actually generate the route-maps (and associated peering configurations) from some kind of provisioning database via a script. The idea is that ...
rnxrx's user avatar
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4 votes
Accepted

Hardware implementations of BFD

I know that at least some Cisco routers and switches "implement" BFD in hardware. The problem they address is as follows. In BFD there is a requirement that packets be sent very often, something like ...
mere3ortal's user avatar
  • 2,416
4 votes
Accepted

diff btw PTSN and DSL?

You can't compare those two. They are completely different things. xDSL is a family of point-to-point line protocols which can transport just about any digital data over a few hundred meters to a few ...
Zac67's user avatar
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4 votes
Accepted

Network design question for datacenter

The 5600-series can switch 40G at line rate (...as in full 40Gbit/s flows) but won't ever be able to switch full 100G interfaces (nb - fabric is limited to 40G flows). The 5500 can only support 40G ...
rnxrx's user avatar
  • 6,114
4 votes

Re-tagging identically tagged VLANs

Some Cisco switches support "vlan mapping". You'd do this (for your example): Switch(config)#int <wan-1> Switch(config-if)#switchport mode trunk Switch(config-if)#switchport vlan mapping X A ...
mere3ortal's user avatar
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4 votes
Accepted

What is difference between "topology of network" and "geometry of network"?

Converted from comment Most of the time, "network geometry" doesn't make too much sense. You build networks as a bus, in stars, trees, rings but these are topologies. Above the actual topology you ...
Zac67's user avatar
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4 votes
Accepted

What are the differences between injecting the default route to IGP using a static route or using a generated route?

Static route This route will be installed as long as its next-hop is reachable. The default route Preference is 5. Static routes are simpler and are appropriate when there's no routing protocol ...
Jeff Wheeler's user avatar
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4 votes
Accepted

For IPv6, How much processing delay difference between using /64 and /127 for Core network interconnection?

Short answer: none. A router in such a network would be using TCAM hardware (ternary content-addressable memory). Normal RAM is used by addressing a cell (bit/byte/word) and then reading or writing ...
Zac67's user avatar
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3 votes

F5 as a backbone router

Not enough points to comment in agreement with mxrx yet, or vote his answer up, so I'll answer in agreement. The BIG-IP can do routing well yes, but in support of application delivery. But if you ...
Jason Rahm's user avatar
3 votes
Accepted

Preventing Load balancing in EIGRP

If you simply want to prevent load balancing, then you can use the maximum-paths command in EIGRP to do that. Just set it to 1: router eigrp 1 maximim-paths 1 EIGRP Commands: maximum-paths (...
Ron Maupin's user avatar
  • 99.4k
3 votes

Network distribution/core design implementation

The 3650 will switch layer-2 at wire speed, even if you have it fully populated. You cannot get more traffic into the switch than it has ports. When it comes to routing, there are too many variables ...
Ron Maupin's user avatar
  • 99.4k

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